On a production line along which robots are operated, if a robot fails, the robot is sometimes temporarily removed from the production line and then reinstalled after being repaired. Further, a robot is sometimes relocated when the production line on which robots are operated is to be switched and when operators work on the production line.
When a robot is installed in a working position, a robot operator performs a teaching operation for teaching the robot the transport route of workpieces. In the teaching operation, the robot operator causes the robot to store a teaching position, which is a point on the transport route. When a robot that has been moved from a working position on the production line is reinstalled in the same working position, some changes occur in the positional relation between the transport route of the workpieces and the robot. Further, when a robot is relocated from the initial working position to another working position and when a robot that has been moved from the initial working position is reinstalled in the original working position, the robot operator sometimes performs the teaching operation on the robot again.
Patent Literature 1 discloses a direct teaching device that acquires teaching data by positioning an arm attached with a tactile sensor in a teaching position. When an operator moves the arm to a desired teaching position, the direct teaching device acquires the coordinates of the teaching position.